As is well known in the art, sailboards are generally steered using a hand-operated tiller while sitting on the deck, such as in a Sunfish, Sailfish, or other types of sailboats. Alternately, others such as conventional sailboards, are steered from a standing position using the arms to alter the angle of the mast and boom relative to the sailboard and the prevailing wind. Another method of steering a sailboard is to lie prone on the deck, belly-down with the head pointing toward the bow and the feet protruding past the stern, as can be seen from U.S. Pat. No. 3,902,441, granted to Roger A. Scholle on Sep. 2, 1975. Another patent which discloses a sailing craft operated by a person lying prone on the hull is shown and described in U.S. Pat. No. 3,793,973, granted Feb. 26, 1974 to George W. Patterson. The feet can then operate a rudder device by pressing against a cross bar. The left foot can press against the left half of the cross bar to steer the boat to the right and the right foot can press against the right half of the cross bar to steer the boat to the left. The advantages of this kind of steering mechanism are as follows: it allows for a smaller, more portable sailing craft than a conventional sailboat, which involves a cockpit, or than a Sailfish, which requires a larger hull for stability while sitting. It also provides certain advantages over a Windsurfer-type sailboard that requires standing because the sailboard requires learning a very difficult and unconventional method of sailing. Standing sailboarding is very much unlike sailing and is exceedingly difficult to learn because it requires athleticism, arm strength, agility and balance, as well as a skill of steering and operation which is very much different from conventional sailboating. Unlike the standing sailboard, a sailboard operated from a prone position is operated in the conventional manner of single-sail sailboats, using a mainsheet and a rudder. It is thus easy to adapt to for persons with even a minimum of sailing experience. Furthermore, it does not require the athleticism and agility of a standup-operated sailboard.
Important to a sailboard operated from a prone position is the foot-operated rudder, as such rudder allows the sailboard to be used from a prone position since from such a position the feet can efficiently operate the rudder. In addition, such a configuration allows one hand to control the mainsheet while the other is free to grasp the gunwhale or otherwise help in balancing. In addition, under adversely rough or calm conditions, steering with the feet allows the operator to paddle instead of sail, since both arms are free to paddle if the mainsheet is released. Under rough conditions, it is advisable to let go of the mainsheet anyway and allow the sail to flap.
The prior patented inventions noted hereinabove both disclose the construction and operation of foot-operated rudders. In USP No. 3,902,441, the rudder configuration involves a rudder permanently connected to the hull that has two engageable blades that fold down to permit flat stowage of the rudder on the hull. The crux of this patent is to allow stacking of craft one atop another for easy transport and stowage of several craft as might be appropriate in a summer camp. However, such a purpose requires a method of securing the rudder to the deck for transport and is thus unwieldy. The purpose is also not clearly relevant since removable rudders are simple to carry and store. More importantly, the purpose requires giving up too much in terms of simplicity, efficiency and economy of design and setup operation. Thus, the aforesaid rudder configuration is somewhat cumbersome in design, and has proved difficult to produce and difficult to set up for operation. It is also expensive to fabricate since it requires two folding flaps which must be hinged. In addition, a fastening device is necessary to hold the two flaps together.
Secondly, because the footbar forms part of the backboard on which the rudder blades are hinged, the footbar cannot be adjusted. The adjustment of the footbar from the stern of the boat is most important and critical in that because an operator's weight distribution bow to aft is determined by his distance from the contact between his feet and the footbar, and thus his center of gravity's location determines how the sailboat rides in the water. For short operators the stern of the boat tends to drag in the water while the bow sticks up above the water. When the bow rides high out of the water it compromises efficiency and stability.
Thus, the disadvantages of the present configurations involves excessive complexity of design and construction, cumbersomeness in setting-up for operation, as well as the inability to adjust rudder for operator height or length when in the prone position on the sail board.
Another disadvantage of the present configurations deals with the retractable centerboard which is difficult to produce since it requires specific fittings having very precise proportions. Such fittings include the centerboard blade, which can expand or warp and thus stick in the centerboard trunk, as well as controls for retraction of said blade, which can wear and break. In this connection, it should be recognized that the centerboard assemblage adds weight to the craft since a watertight centerboard trunk is required.
Another particular disadvantage of the centerboard which is used in U.S. Pat. No. 3,902,441 is that it does not provide the lateral stability that could be achieved with leeboards, which serve the same purpose. The use of leeboards are particularly helpful in stabilizing sailboards, which are relatively unstable as compared with sailboats. The sailboard in U.S. Pat. No. 3,902,441 is designed with the option of mounting outrigger foils for stability. Although such outriggers are not necessary for operating the craft, they are even less useful if the centerboard is replaced by leeboards. Leeboards, which are a standard feature of many sailboats, are not considered outriggers by the industry.
With reference to U.S. Pat. No. 3,793,973, this patent utilizes a rudder that may appear to partially meet both of the disadvantages of the previously mentioned rudder, but sacrifices several of its advantages, and it partially accomplishes the first objection of complex rudder design by utilizing a single blade rudder with fixed footbar. The disadvantages of this configuration will be discussed below. The second objection, lack of adjustability, is accomplished in this patent by utilizing an adjustable rudder boom that connects at one end to the rudder and at the other end telescopes from a hollow shaft built into the hull of the craft. When the operator wishes to adjust the length of the craft he slides the boom in or out of the shaft and tightens the boom with a clamp.
Of the several disadvantages with this configuration, the method of adjustment is most difficult, and secondly, the hull is necessarily shorter than is preferred for craft stability because one hull size fits all individuals. Short individuals prefer the rudder boom to be adjusted far inward relative to taller people and tall individuals, on the other hand, require that the boom be extended far out from the stern of the hull. For tall individuals the knees tend to drag in the water, reducing efficiency and causing discomfort in cold water. Thirdly, since the configuration requires a short hull to meet its intended purpose, the speed of the craft is seriously reduced and the stability of the craft is compromised. In as much as hull length contributes to velocity and stability, it is for these reasons of stability, etc., that the craft is of necessity equipped with hydrofoil outriggers. Such outriggers slow the boat down further. In addition, the distant rudder with its wide footbar acts as a second hull, slowing the boat down even further.
Another disadvantage of such rudder design is that the materials used in construction must be buoyant. If they are not, the rudder will submerge. Submersion may cause the rudder boom to drag in the water, clog the adjustment holes in the boom with water-borne weeds and debris, and put pressure on the shaft and its watertight casing.
An additional disadvantage of such rudder design is that, unlike the rudder of U.S. Pat. No. 3,902,441, the rudder is not pivotable in a verticle plane. It thus can be damaged or can impede progress when striking submerged objects. Furthermore, such design is a relatively complicated production project, requiring a watertight boom shaft set in the hull.